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face-WRITING AP* NET IONIC EQUATIONS
AP equation sets are found in the free-response section of the AP test. You are given eight equations and you must choose to answer five of these.** The equations are of mixed types. The section is worth 15 points and is 15 % of the free response grade. Free response is 55% of the total AP test grade.
All AP equations "work". In each case, a reaction will occur. These equations need to be written in net ionic form. All spectator ions must be left out and all ions must be written in ionic form. All molecular substances and nonsoluble compounds must be written together (not ionized!). Weak electrolytes, such as acetic acid, are not ionized. Solids and pure liquids are written together, also.
A saturated solution is written in ionic form while a suspension is written together. AP equations do not need to be balanced. Don't waste your time on balancing!
Each equation is worth a total of 3 points. One point is given for the correct reactants and two points for all correct products. If a reaction has three products, one point is given for two correct products and two points for all correct products. Leaving in the spectator ions will result in a one point deduction on the equation set (not 1 point per problem).
The best way to prepare for the equation section of the AP test is to practice lots of equations. The equation sets are similar and some equations show up year after year. When you are reading an equation, first try to classify it by type. If it says anything about acidic or basic solution, it is redox. If you are totally stuck, look up the compounds in the index of your book or other reference books and try to find
information that will help you with the equation. All reactions do not fit neatly into the five types of reactions that you learned in Chemistry I. Save the reactions that you write and practice them again before the AP test in May.
Kristen Henry Jones 01/28/99
Double Replacement (metathesis)
Two compounds react to form two new compounds. No changes in oxidation numbers occur. All double replacement reactions must have a "driving force" that removes a pair of ions from solution.
Formation of a precipitate: A precipitate is an insoluble substance formed by the
reaction of two aqueous substances. Two ions bond together so strongly that water can not pull them apart. You must know your solubility rules to write these net ionic equations (see next page)
Ex. Solutions of silver nitrate and lithium bromide are mixed.
Ag + Br Æ AgBr
Formation of a gas: Gases may form directly in a double replacement reaction or can
form from the decomposition of a product such as H2CO3 or H2SO3.
Common gasses: CO2, SO2, SO3, H2S, NO2, NH3, O2, H2
Ex. Excess hydrochloric acid solution is added to a solution of potassium sulfite.
H+ + SO32-Æ H20 + SO2
Ex. A solution of sodium hydroxide is added to a solution of ammonium chloride.
OH- + NH4+ Æ NH3 + H2O
Formation of a molecular substance: When a molecular substance such as water or
acetic acid is formed, ions are removed from solution and the reaction "works".
Ex. Dilute solutions of lithium hydroxide and hydrobromic acid are mixed.
OH- + H+ Æ H2O (HBr, HCI, and HI are strong acids)
Ex. Gaseous hydrofluoric acid reacts with solid silicon dioxide.
Writing Net Ionic Equations 3
Solubility Rules
These are strong electrolytes (100% ionized ) and written as ions
1. Strong Acids: HCl, HBr, HI, H2SO4, HNO3, HClO4, HClO3
2. Strong Bases: Hydroxides of group IA and IIA(Ba, Sr, Ca are marginal Be and Mg are WEAK)
3. Soluble Salts (see table): (ionic compounds: metal/nonmetal)
ALWAYS SOUBLE IF IN A COMPOUND EXCEPT WITH
NO3-, Group IA, NH4+, C2H3O2-, ClO4-, ClO3- No Exceptions
Cl- , Br- , I- Pb, Ag, Hg22+
SO42- Pb, Ag, Hg22+
Ca, Sr, Ba
If it does not fit one of the three rules above, assume it is INSOLUBLE or a WEAK ELECTROLYTE (and written together). This won’t always be correct, but will cover most of the situations.
Also, GASES, PURE LIQUIDS, and SOLIDS are non-electrolytes.
Writing Net Ionic Equations 4
Single Replacement
Reaction where one element displaces another in a compound. One element is oxidized and another is reduced.
A + BC ÆB + AC
Active metals replace less active metals or hydrogen from their compounds in
aqueous solution. Use an activity series or a reduction potential table to determine
activity. The more easily oxidized metal replaces the less easily oxidized metal. The metal with the most negative reduction potential will be the most active.
Ex. Magnesium turnings are added to a solution of iron(III) chloride. Mg + Fe 3+ Æ Fe + Mg2+
Ex. Sodium is added to water.
Na + H2O Æ Na+ + OH- + H2
Active nonmetals replace less active nonmetals from their compounds inaqueous
solution. Each halogen will displace less electronegative (heavier) halogens from their
binary salts.
Ex. Chlorine gas is bubbled into a solution of potassium iodide.
C12 + I- Æ I2 + Cl
-Tricky redox reactions that appear to be ordinary single replacementreactions:
x Hydrogen reacts with a hot metallic oxide to produce the elemental metal and water.
Ex. Hydrogen gas is passed over hot copper(II) oxide.
H2+ CuO Æ Cu2+ + H2O
x A metal sulfide reacts with oxygen to produce the metallic oxide and sulfur dioxide.
Writing Net Ionic Equations 5
x Copper reacts with concentrated sulfuric acid to produce copper(II) sulfate, sulfur dioxide, and water.
x Copper reacts with dilute nitric acid to produce copper(II) nitrate, nitrogen monoxide and water.
Anhydrides
x Anhydride means "without water"
x Water is a reactant in each of these equations.
Nonmetallic oxides (acidic anhydrides) plus water yield acids.
Ex. Carbon dioxide is bubbled into water.
CO2 + H2O Æ H2CO3
Metallic oxides (basic anhydrides) plus water yield bases.
Ex. Solid sodium oxide is added to water.
Na2O + H2OÆNa+ + OH
-Metallic hydrides (ionic hydrides) plus water yield metallic hydroxides and hydrogen gas.
Ex. Solid sodium hydride is added to water.
NaH +H2O ÆNa+ + OH- + H2
Phosphorus halides react with water to produce an acid of phosphorus (phosphorous acid or phosphoric acid) and a hydrohalic acid. The oxidation number of the phosphorus remains the same in both compounds. Phosphorus oxytrichloride reacts with water to make the same products.
Ex. Phosphorus tribromide is added to water.
PBr3 + H2O Æ H3PO3 + H+ + Br
OXIDATION-REDUCTION REACTIONS
Redox reactions involve the transfer of electrons. The oxidation numbers of at least twoelements must change. Single replacement, some combination and some
decompositionreactions are redox reactions.
To predict the products of a redox reaction, look at the reagents given to see if there is both an oxidizing agent and a reducing agent.
When a problem mentions an
acidic or
basic solution, it is probably redox.
Common oxidizing agents Products formed
MnO4- in acidic solution Mn2+
MnO2 in acidic solution Mn2+
MnO4- in neutral or basic solution MnO2 (s) Cr2O7- in acidic solution Cr3+
HNO3, concentrated NO2
HNO3, dilute NO
H2SO4, hot, concentrated SO2
metal-ic ions metal-ous ions
free halogens halide ions
Na2O2 NaOH
HC1O4 Cl
-H2O2 H2O
Common reducing agents Products formed
halide ions free halogen
free metals metal ions
sulfite ions or SO2 sulfate ions
nitrite ions nitrate ions
free halogens, dilute basic solution hypohalite ions free halogens, conc. basic solution halate ions
metal-ous ions metal-ic ions
H2O2 O2
C2O42- CO2
Ex. A solution of tin(II) chloride is added to an acidified solution of potassium permanganate. Sn 2+ + H+ + MnO4- Æ Sn 4+ + Mn2+ + H2O
Ex. A solution of potassium iodide is added to an acidified solution of potassium dichromate. I- + H+ + Cr2O7- Æ Cr3+ + I2 + H2O
Ex. Hydrogen peroxide solution is added to a solution of iron(II) sulfate.
H2O2 + Fe2+Æ Fe3+ + H2O
COMPLEX ION REACTIOINS
Complex ion- the combination of a central metal ion and its ligands
Ligand- group bonded to a metal ion
Coordination compound- a neutral compound containing complex ions [Co(NH3)6]Cl3
(NH3 is the ligand, [Co(NH3)6]3+ is the complex ion)
Common complex ions formed in AP equations:
Complex ion Name Formed from:
[AI(OH)4]- tetrahydroxoaluminate ion (Al or Al(OH)3 or Al 3+ + OH-)
[Al(H2O)6]3+ hexaquaaluminum ion (Al3+ in H2O)
[Ag(NH3)2]+ dimminesilver(I) ion (Ag+ + NH3)
[Zn(OH)4]2- tetrahydroxozincate ion (Zn(OH)2 + OH-)
[Zn(NH3)4]2+ tetramminezinc ion (Zn2+ + NH3)
[Cu(NH3)4]2+ tetramminecopper(II) ion (Cu+2+ NH3)
[Cd(NH3)4]2+ tetramminecadmium(II) ion (Cd2+ + NH3)
[FeSCN]+2 thiocyanoiron(III) ion (Fe +3 + SCN-)
[Ag(CN)2]- dicyanoargentate (I) ion (Ag+ + CN-)
Adding an acid to a complex ion will break it up. If HCl is added to a silver
complex, AgCl(s) is formed. If an acid is added to an ammonia complex, NH4+ is
Writing Net Ionic Equations 9
Kristen Henry Jones 01/28/99
DECOMPOSITION REACTIONS
Reactions where a compound breaks down into two or more elements or compounds. Heat, electrolysis, or a catalyst is usually necessary.
Acompound may break down to produce two elements.
Ex. Molten sodium chloride iselectrolyzed.
NaCl Æ Na+ + C12
Acompound may break down to produce an element and a compound.
Ex. A solution of hydrogen peroxide is decomposed catalytically.
H2O2 Æ H2O + O2
A compound may break down to produce two compounds.
Ex. Solid magnesium carbonate is heated.
MgCO3 Æ Mg + CO2
Metallic carbonates break down to yield metallic oxides and carbon dioxide,
Metallic chlorates break down to yield metallic chlorides and oxygen.
Hydrogen peroxide decomposes into water and oxygen.
Ammonium carbonate decomposes into ammonia, water and carbon dioxide.
Sulfurous acid decomposes into water and sulfur dioxide.
Writing Net Ionic Equations 10
ADDITION REACTIONS
Two or more elements or compounds combine to form a single product.
A group IA or IIA metal may combine with a nonmetal to make a salt.
Ex. A piece of lithium metal is dropped into a container of nitrogen gas.
Li + N2 Æ Li3N
Two nonmetals may combine to form a molecular compound. The oxidation number of the less electronegative element is often variable depending upon
conditions. Generally, a higher oxidation state of one nonmetal is obtainedwhen
reacting with an excess of the other nonmetal.
Ex. P4 + 6 Cl2 Æ 4 PCl3 limited Cl P4 + 10 Cl2 Æ 4 PCl5 excess Cl
When an element combines with a compound, you can usually sum up all of the elements on the product side.
Ex. PCl3 + C12 ÆPCl5
Two compounds combine to form a single product.
Ex. Sulfur dioxide gas is passed over solid calcium oxide.
SO2 + CaO Æ CaSO3
Ex. The gases boron trifluoride and ammonia are mixed.
BF3 + NH3 Æ H3NBF3
A metallic oxide plus carbon dioxide yields a metallic carbonate. (Carbon keeps
the same oxidation state)
A metallic oxide plus sulfur dioxide yields a metallic sulfite. (Sulfur keeps the
same oxidation state)
A metallic oxide plus water yields a metallic hydroxide.
Writing Net Ionic Equations 11
ACID-BASE NEUTRALIZATION REACTIONS
Acids react with bases to produce salts and water. One mole of hydrogen ions react
with one mole of hydroxide ions to produce one mole of water. Watch out for information about quantities of each reactant! Remember which acids are strong (ionize completely) and which are weak (write as molecule).
Sulfuric acid (strong acid) can be written as H+ and SO42- or as H+ and HSO4-.
Ex. A solution of sulfuric acid is added to a solution of barium hydroxide until the same number of moles of each compound as been added.
H+ + SO42- + Ba2+ + OH- Æ BaSO4 + H2O
Ex. Hydrogen sulfide gas is bubbled through excess potassium hydroxide solution.
H2S + OH- Æ H2O + S
Watch out for substances that react with water before reacting with an acid ora
base. These are two-step reactions.
Ex. Sulfur dioxide gas is bubbled into an excess of a saturated solution of calcium hydroxide.
Writing Net Ionic Equations 12
COMBUSTION REACTIONS
Elements or compounds combine with oxygen.
Hydrocarbons or alcohols combine with oxygen to form carbon dioxide and water.
Ammonia combines with limited oxygen to produce NO and water and with
excess oxygen to produce N02 and water.
Nonmetallic hydrides combine with oxygen to form oxides and water.
Nonmetallic sulfides combine with oxygen to form oxides and sulfur dioxide.
Ex. Carbon disulfide vapor is burned in excess oxygen.
CS2 + O2Æ CO2 + SO2
Ex. Ethanol is burned completely 'in air.
Adapted from an original document by Kristen Henry Jones
AP CHEMISTRY EQUATIONS BY TYPE
Double Replacement
1. Hydrogen sulfide is bubbled through a solution of silver nitrate.
2. An excess of sodium hydroxide solution is added to a solution of magnesium nitrate. 3. Solutions of sodium iodide and lead nitrate are mixed.
4. A solution of ammonia is added to a solution of ferric chloride. 5. Solutions of silver nitrate and sodium chromate are mixed.
6. Excess silver acetate is added to a solution of trisodium phosphate. 7. Manganese(II) nitrate solution is mixed with sodium hydroxide solution.
8. A saturated solution of calcium hydroxide is added to a solution of magnesium chloride. 9. Hydrogen sulfide gas is added to a solution of cadmium nitrate.
10. Dilute sulfuric acid is added to a solution of barium acetate.
11. A precipitate is formed when solutions of trisodium phosphate and calcium chloride are mixed. 12. A solution of copper(II) sulfate is added to a solution of barium hydroxide.
13. Equal volumes of dilute equimolar solutions of sodium carbonate and hydrochloric acid are mixed.
14. Solid barium peroxide is added to cold dilute sulfuric acid.
15. Excess hydrochloric acid solution is added to a solution of potassium sulfite. 16. Dilute sulfuric acid is added to a solution of barium chloride.
17. A solution of sodium hydroxide is added to a solution of ammonium chloride. 18. Dilute hydrochloric acid is added to a solution of potassium carbonate.
19. Gaseous hydrogen sulfide is bubbled through a solution of nickel(II) nitrate. 20. A solution of sodium sulfide is added to a solution of zinc nitrate.
21. Concentrated hydrochloric acid is added to solid manganese(II) sulfide. 22. Solutions of tri-potassium phosphate and zinc nitrate are mixed.
23. Dilute acetic acid solution is added to solid magnesium carbonate. 24. Gaseous hydrofluoric acid reacts with solid silicon dioxide.
25. Equimolar amounts of trisodium phosphate and hydrogen chloride, both in solution, are mixed.
26. Ammonium chloride crystals are added to a solution of sodium hydroxide. 27. Hydrogen sulfide gas is bubbled through a solution of lead(II) nitrate. 28. Solutions of silver nitrate and sodium chromate are mixed.
29. Solutions of sodium fluoride and dilute hydrochloric acid are mixed.
30. A saturated solution of barium hydroxide is mixed with a solution of iron(III) sulfate. 31. A solution of ammonium sulfate is added to a potassium hydroxide solution.
32. A solution of ammonium sulfate is added to a saturated solution of barium hydroxide. 33. Dilute sulfuric acid is added to solid calcium fluoride.
34. Dilute hydrochloric acid is added to a dilute solution of mercury(I) nitrate. 35. Dilute sulfuric acid is added to a solution of lithium hydrogen carbonate. 36. Dilute hydrochloric acid is added to a solution of potassium sulfite.
37. Carbon dioxide gas is bubbled through water containing a suspension of calcium carbonate. 38. Excess concentrated sulfuric acid is added to solid calcium phosphate.
39. Hydrogen sulfide gas is bubbled into a solution of mercury(II) chloride. 40. Solutions of zinc sulfate and sodium phosphate are mixed.
42. Solutions of manganese(II) sulfate and ammonium sulfide are mixed.
43. Excess hydrochloric acid solution is added to a solution of potassium sulfite.
Single Replacement
1. A piece of aluminum metal is added to a solution of silver nitrate. 2. Aluminum metal is added to a solution of copper(II) chloride. 3. Hydrogen gas is passed over hot copper(II) oxide.
4. Small chunks of solid sodium are added to water.
5. Calcium metal is added to a dilute solution of hydrochloric acid. 6. Magnesium turnings are added to a solution of iron(III) chloride. 7. Chlorine gas is bubbled into a solution of sodium bromide. 8. A strip of magnesium is added to a solution of silver nitrate. 9. Solid calcium is added to warm water.
10. Liquid bromine is added to a solution of potassium iodide. 11. Chlorine gas is bubbled into a solution of potassium iodide. 12. Lead foil is immersed in silver nitrate solution.
13. Solid zinc strips are added to a solution of copper(II) sulfate. 14. Sodium metal is added to water.
15. A bar of zinc metal is immersed in a solution of copper(II) sulfate. 16. A small piece of sodium metal is added to distilled water.
Anhydrides
1. Excess water is added to solid calcium hydride. 2. Solid lithium hydride is added to water.
3. Liquid phosphorus trichloride is poured into a large excess of water. 4. Solid sodium carbide is added to an excess of water.
5. Solid magnesium nitride is added to excess deuterium oxide. 6. Water is added to a sample of pure phosphorus tribromide. 7. Water is added to a sample of pure sodium hydride.
8. Dinitrogen trioxide gas is bubbled into water.
9. Solid phosphorus pentachloride is added to excess water. 10. Solid dinitrogen pentoxide is added to water.
11. Sulfur trioxide gas is added to excess water. 12. Solid sodium oxide is added to water.
13. Phosphorus(V) oxytrichloride is added to water. 14. Water is added to a sample of solid magnesium nitride. 15. Solid potassium oxide is added to water.
16. Solid sodium cyanide is added to water.
17. Trisodium phosphate crystals are added to water. 18. Solid lithium oxide is added to excess water. 19. Solid barium oxide is added to distilled water. 20. Solid calcium hydride is added to distilled water.
21. Phosphorous(V) oxide powder is sprinkled over distilled water.
Combustion
1. Lithium metal is burned in air.
Adapted from an original document by Kristen Henry Jones 3. Gaseous diborane, B2H6, is burned in excess oxygen.
4. A piece of solid bismuth is heated strongly in oxygen. 5. Solid zinc sulfide is heated in an excess of oxygen. 6. Propanol is burned completely in air.
7. Excess oxygen gas is mixed with ammonia gas in the presence of platinum. 8. Gaseous silane, SiH4, is burned in oxygen.
9. Ethanol is completely burned in air.
10. Solid copper(II) sulfide is heated strongly in oxygen gas. 11. Ethanol is burned in oxygen.
12. Carbon disulfide vapor is burned in excess oxygen.
Redox
1. Iron(III) ions are reduced by iodide ions.
2. Potassium permanganate solution is added to concentrated hydrochloric acid.
3. Magnesium metal is added to dilute nitric acid, giving as one of the products a compound in which the oxidation number for nitrogen is -3.
4. A solution of potassium iodide is electrolyzed.
5. Potassium dichromate solution is added to an acidified solution of sodium sulfite. 6. Solutions of potassium iodide, potassium iodate, and dilute sulfuric acid are mixed. 7. A solution of tin(II) sulfate is added to a solution of iron(III) sulfate.
8. Metallic copper is heated with concentrated sulfuric acid.
9. Manganese(IV) oxide is added to warm, concentrated hydrobromic acid. 10. Chlorine gas is bubbled into cold dilute sodium hydroxide.
11. Solid iron(III) oxide is heated in excess carbon monoxide.
12. Hydrogen peroxide solution is added to acidified potassium iodide solution. 13. Hydrogen peroxide is added to an acidified solution of potassium dichromate.
14. Sulfur dioxide gas is bubbled through an acidified solution of potassium permanganate. 15. A solution containing tin(II) ions is added to an acidified solution of potassium dichromate. 16. Solid silver sulfide is warmed with dilute nitric acid.
17. A dilute solution of sulfuric acid is electrolyzed between platinum electrodes. 18. Pellets of lead are dropped into hot sulfuric acid.
19. Potassium permanganate solution is added to a solution of oxalic acid, H2C2O4, acidified
with a few drops of sulfuric acid.
20. Powdered iron is added to a solution of iron(III) sulfate.
21. A concentrated solution of hydrochloric acid is added to powdered manganese dioxide and gently heated.
22. A strip of copper metal is added to a concentrated solution of sulfuric acid. 23. Copper(II) sulfide is oxidized by dilute nitric acid.
24. A solution of copper(II) sulfate is electrolyzed using inert electrodes.
25. A solution of potassium iodide is added to an acidified solution of potassium dichromate. 26. Hydrogen peroxide solution is added to a solution of iron(II) sulfate.
27. Solid silver is added to a dilute nitric acid (6M) solution.
28. A solution of formic acid, HCOOH, is oxidized by an acidified solution of potassium dichromate.
29. A piece of iron is added to a solution of iron(III) sulfate.
31. A solution of tin(II) chloride is added to a solution of iron(III) sulfate.
32. Concentrated hydrochloric acid solution is added to solid manganese(IV) oxide and the reactants are heated.
33. A strip of copper is immersed in dilute nitric acid.
34. Potassium permanganate solution is added to an acidic solution of hydrogen peroxide. 35. Solid copper is added to a dilute nitric acid solution.
36. Chlorine gas is bubbled into a cold solution of dilute sodium hydroxide.
37. A solution of potassium permanganate is mixed with an alkaline solution of sodium sulfite. 38. Solid sodium dichromate is added to an acidified solution of sodium iodide.
39. Hydrogen gas is passed over hot iron(III) oxide.
40. Solutions of potassium iodide and potassium iodate are mixed in acid solution. 41. Hydrogen peroxide is added to an acidified solution of sodium bromide. 42. Chlorine gas is bubbled into a cold, dilute solution of potassium hydroxide. 44. A solution of iron(II) nitrate is exposed to air for an extended period of time.
45. A stream of chlorine gas is passed through a solution of cold, dilute sodium hydroxide. 46. A solution of tin(II) chloride is added to an acidified solution of potassium permanganate. 47. A concentrated solution of hydrochloric acid is added to solid potassium permanganate. 48. A solution of potassium dichromate is added to an acidified solution of iron(II) chloride.
Acid-Base Neutralizations
1. Solutions of ammonia and hydrofluoric acid are mixed.
2. Hydrogen sulfide gas is bubbled through a solution of potassium hydroxide.
3. A solution of sulfuric acid is added to a solution of barium hydroxide until the same number of moles of each compound has been added.
4. A solution of sodium hydroxide is added to a solution of sodium dihydrogen phosphate until the same number of moles of each compound has been added.
5. Dilute nitric acid is added to crystals of pure calcium oxide.
6. Equal volumes of 0.1-molar sulfuric acid and 0.1-molar potassium hydroxide are mixed. 7. A solution of ammonia is added to a dilute solution of acetic acid.
8. Excess sulfur dioxide gas is bubbled through a dilute solution of potassium hydroxide. 9. Sulfur dioxide gas is bubbled into an excess of a saturated solution of calcium hydroxide.
10. A solution of sodium hydroxide is added to a solution of calcium hydrogen carbonate until the number of moles of sodium hydroxide added is twice the number of moles of the calcium salt.
11. Equal volumes of 0.1M hydrochloric acid and 0.1M sodium monohydrogen phosphate are mixed.
12. Hydrogen sulfide gas is bubbled through excess potassium hydroxide solution. 13. Ammonia gas and carbon dioxide gas are bubbled into water.
14. Carbon dioxide gas is bubbled through a concentrated solution of sodium hydroxide. 15. Acetic acid solution is added to a solution of sodium hydrogen carbonate.
16. Excess potassium hydroxide solution is added to a solution of potassium dihydrogen phosphate. 17. Carbon dioxide gas is bubbled through a concentrated solution of potassium hydroxide.
Complex Ions
Adapted from an original document by Kristen Henry Jones
2. An excess of nitric acid solution is added to a solution of tetraaminecopper(II) sulfate. 3. Dilute hydrochloric acid is added to a solution of diamminesilver(I) nitrate.
4. Solid aluminum nitrate is dissolved in water.
5. A suspension of copper(II) hydroxide is treated with an excess of ammonia water. 6. A solution of diamminesilver(I) chloride is treated with dilute nitric acid.
7. An excess of concentrated ammonia solution is added to freshly precipitated copper(II) hydroxide.
8. Excess dilute nitric acid is added to a solution containing the tetraaminecadmium(II) ion. 9. An excess of ammonia is bubbled through a solution saturated with silver chloride. 10. Solid aluminum oxide is added to a solution of sodium hydroxide.
11. A concentrated solution of ammonia is added to a solution of zinc iodide.
12. An excess of sodium hydroxide solution is added to a solution of aluminum chloride. 13. A concentrated solution of ammonia is added to a solution of copper(II) chloride. 14. Excess concentrated sodium hydroxide solution is added to solid aluminum hydroxide. 15. Excess concentrated ammonia solution is added to a suspension of silver chloride,
16. Pellets of aluminum metal are added to a solution containing an excess of sodium hydroxide.
17. A suspension of zinc hydroxide is treated with concentrated sodium hydroxide solution. 18. Silver chloride is dissolved in excess ammonia solution.
19. Sodium hydroxide solution is added to a precipitate of aluminum hydroxide in water. 20. A drop of potassium thiocyanate is added to a solution of iron(III) chloride.
21. A concentrated solution of ammonia is added to a suspension of zinc hydroxide.
22. Excess concentrated potassium hydroxide solution is added to a precipitate of zinc hydroxide.
23. A solution of ammonium thiocyanate is added to a solution of iron(III) chloride. 24. Excess sodium cyanide is added to a solution of silver nitrate.
Addition
1. The gases boron trifluoride and ammonia are mixed.
2. A mixture of solid calcium oxide and solid tetraphosphorus decaoxide is heated. 3. Solid calcium oxide is exposed to a stream of carbon dioxide gas.
4. Solid calcium oxide is heated in the presence of sulfur trioxide gas. 5. Calcium metal is heated strongly in nitrogen gas.
6. Excess chlorine gas is passed over hot iron filings.
7. Powdered magnesium oxide is added to a container of carbon dioxide gas. 8. A piece of lithium metal is dropped into a container of nitrogen gas. 9. Magnesium metal is burned in nitrogen gas.
10. Sulfur dioxide gas is passed over solid calcium oxide.
11. Samples of boron trichloride gas and ammonia gas are mixed.
Decomposition
1. A solution of hydrogen peroxide is heated. 2. Solid magnesium carbonate is heated.
3. A solution of hydrogen peroxide is catalytically decomposed.
4. Solid potassium chlorate is heated in the presence of manganese dioxide as a catalyst. 5. Sodium hydrogen carbonate is dissolved in water.